Thick clouds have obscured satellite views of Cleveland for the last 10 hours. No plumes have been visible in satellite data since 16:00 AKDT yesterday (midnight UTC). Satellite data from early yesterday evening continue to show strong thermal anomalies near Cleveland's summit. These data strongly suggest the presence of lava at Cleveland.

The eruption of Okmok Volcano continues. The character of seismicity has changed in the last 12 hours from episodic, high-amplitude pulses to nearly continuous, mid-level volcanic tremor. Recent satellite data continue to show older plumes drifting away from Okmok toward the E/SE. Weather clouds have prevented unobscured views of the volcano over the last 10 hours.

Stronger explosive activity could resume at any time with little or no warning.

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

VOLCANO ALERT LEVELS

NORMALVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

ADVISORYVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

WATCHVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway but poses limited hazards.

WARNINGHazardous eruption is imminent, underway, or suspected.

AVIATION COLOR CODES

GREENVolcano is in typical background, noneruptive state or, after a change from a higher level, volcanic activity has ceased and volcano has returned to noneruptive background state.

YELLOWVolcano is exhibiting signs of elevated unrest above known background level or, after a change from a higher level, volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

ORANGEVolcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain, OR eruption is underway with no or minor volcanic-ash emissions [ash-plume height specified, if possible].

REDEruption is imminent with significant emission of volcanic ash into the atmosphere likely OR eruption is underway or suspected with significant emission of volcanic ash into the atmosphere [ash-plume height specified, if possible].